Naphthalimide dyestuffs and process of preparing them



Patented Nov. 8, 1932 (UNITED STATES PATENT:- orncs WILHELM EGKERT, on FRANKFORT-ON-THE-MAIN-HQCHST, GERMANY, ASSIGNOR 'ro w onx, n. Y, A coaronamron OEDELA- v GENERAL ANILINE WORKS, INC., 01? NE WARE nunrnamminnnynsrunrs AND PROCESS on PREPARING THEM No Drawing. Application filed May 7, 1929, Serial No. $51,255, and in- Germany May .18, 1928.

My present invention relates to naphthalimide dyestuffs and to a process of preparing them. i

I have found that water-soluble acid wool 5 dyestuffs are obtainable by causing a halogen sulfo-naphthalic anhydride or a derivative thereof of the general type:

NHR

wherein R stands for alkyl, aryl or aralkyl and X stands for hydrogen or an alkali metal.

The following examples serve to illustrate my invention; the parts being by weight unless otherwise stated:

(1) 40 parts of sulfo-4-bromo-naphthalicanhydride (obtainable by sulfonating 4- bromo-naphthalic anhydride) are heated to 110 C; to 120 C. with 200 parts by volume of ammonia in an autoclave. When the reaction is finished, the hot solution is filtered with suction, the excess of ammonia is expelled and thedyestufl thus obtained which has the following formula:

SOBH

\) SOBH is precipitated in reddish crystals filtered with suction and dried. It dyes Wool from an acid bath clear reddish-orange tints.

WVhen using instead of para-toluidine for instance aniline and proceeding in the manner indicated in Example 2, there is obtained a dyestuif of similar properties but of a little less reddish tint.

When using instead of sulfo--bromonaphthalic-anhydride, as this is done in Examples 1 and 2, the sulfo-4=chloro-naphthalicanhydride (obtainable by sulfonating 4:- chloro-naphthalicanhydride) and condensing with ammonia, aniline, toluidine or the like, the samedyestulfs are obtained.

(3) 25 parts of sulfo-l-chloro-naphthalic acid and anhydride respectively are heated, while stirring, to 60 C..to C. for some hours with 120 parts by volume of an aqueous methyl-amine solution of about 30% strength and are then heated to 90 C. to 100 C. after addition of further 50 parts by volume of the said methylamine solution.

After cooling the dyestufi thus obtained is completely precipitated by addition of, for instance, common salt, filtered by suction, washed with a solution of common salt and finally dried.

The dyestufi' is a deep yellow powder of the following probable constitution:

NBLCH:

It is soluble in water and dyes the animal fiber from an acid bath yellow tints.

I claim:

1. The process which comprises causing a halogen sulfo -naphthalic acid anyhdride compound to react with a compound of the following general formula;

R-NI-L wherein R stands for hydrogen, aryl or alkyl.

2. The process which comprises heating to boiling temperature an aqueous solution of a halogen-sulfo-naphthalic acid anhydride compound in the presence of a compound of the following general formula:

wherein R stands for hydrogen, aryl or alkyl.

3. The process which comprises heating to boiling temperature an aqueous solution of 4- halogen-sulfo-naphthalic acid anhydride in the presence of a compound of the following general formula:

wherein X represents hydrogen or an alkalimetal and R stands for alkyl or aryl, the said dyestuffs dyeing the animal fiber from an acid bath very even and extremely clear tints.

6. As new products, the water-soluble dyestufls of the following probable formula:

wherein X represents hydrogen or an alkali metal and R stands for alkyl or aryl, the said dyestuffs dyeing the animal fiber from an acid bath very even and extremely clear tints.

7. As a new product, a water-soluble dyestuff of the following formula:

N o=o b=o soax NECK;

wherein Xrepresents' hydrogen or an alkali metal, which dyestuff dyes the. animal fiber fromsan acid bath yellow tints.

8. As a new product, the water-soluble dyestufi of the following formula:

wherein X represents hydrogen or an alkali metal, which dyestuff dyes the animal fiber from an acid bath clear reddish-orange tints.

In testimony whereof, I affix my signature.

WILHELM ECKERT. 

